def caesar_encrypt(text, offset):	
    encrypted = ""
    for chara in text:	
        if chara.isalpha():
            shifted = chr(((ord(chara.lower()) - 97 + offset) % 26) + 97) 
            if chara.isupper():
                shifted = shifted.upper( )
        else:	
            shifted = chara
        encrypted += shifted	
    return encrypted	

offset = int(input())	
text = input()	
print(caesar_encrypt(text, offset))	
